jueves, 17 de febrero de 2011

Acufenos: Sección, Expertos, una puesta al dia

2011 Annual Evidence Update on Tinnitus: Expert commentary

Contributing Author: Veronica Kennedy, Consultant Audiovestibular Physician, Bolton PCT

This year in keeping with increased emphasis on evidence based practice, this clinical update looks at the systematic reviews related to tinnitus published over the past year rather than the threads of research.
It is worth mentioning first, however, the new Clinical Knowledge Summary(1) on tinnitus from NHS Evidence. Clinical Knowledge Summaries were created to be a reliable source of evidence-based information and practical 'know how' about the common conditions managed in primary care. The Clinical Knowledge Summary on tinnitus covers different presentations of tinnitus, assessment of tinnitus, possible causes, when to refer onwards and management options in primary and secondary care.
Currently there are no evidence-based guidelines on the management of tinnitus; however, it is helpful to look at the evidence that can inform management decisions. Over the past year, there were 9 critical or systematic reviews related to tinnitus. Most of these relate to treatment. Three of these were from the Cochrane Database. 
One critical review looked at quality and content of web-based patient information(2). Considering that the internet is often the first point of call for people looking for information about tinnitus, I thought this an interesting study. Unsurprisingly the websites hosted by non-commercial bodies provided higher quality information. As audiology services can be limited in some parts of the world, Swanepoel and Hall(3) did a broad review of studies with ‘tele-audiology’ applications looking briefly at internet-based treatment for tinnitus as part of the review.
There were two robust systematic reviews on sound-based therapies. As part of the Cochrane Database systematic reviews, Hobson et al(4) looked at the role of sound therapy, initially in 362 studies. Only six studies met the eligibility criteria of the review. Three of the studies included amplification devices as hearing aids, bone-anchored hearing aids and cochlear implants were considered ’noise-generating’. While there was a subjective benefit with reported in some of the studies, there was no significant differences between the treatment arms.  This systematic review found that there was no evidence for using sound-generating devices as a sole intervention in alleviating tinnitus. Hoare et al(5) looked at the effectiveness of auditory training for tinnitus. Only ten studies out of the 107 initially identified met the selection criteria. The training techniques included adaptive loudness matching and frequency discrimination training. The evidence to support auditory training as a primary treatment for tinnitus was noted to be of low to moderate quality. The importance of using meaningful outcome measures sensitive to change was highlighted in this review.
Kamalski et al(6) looked at health-related quality of life as a measure of treatment outcomes in their systematic review. This study identified six tinnitus-specific questionnaires (THI, TQ, TRQ, TSI, THQ and TSQ) which are considered to assess the quality of life impact of tinnitus. While generally the psychometrics of these questionnaires showed good internal consistency and reproducibility, and most had good construct validity, none of the questionnaires demonstrated an ability to reflect responsiveness to treatment. The study concluded that these measures should therefore not be used to assess effectiveness of intervention therapies. The review did mention a new questionnaire (Tinnitus Functional Index) which is being validated for this purpose.

The second systematic review from the Cochrane Database was on Tinnitus Retraining Therapy (TRT) for tinnitus (7). Although TRT is often mentioned in studies and clinical practice as a therapy, as this review found, most studies referring to TRT used a modified version of this therapy. The search for a randomised controlled trial using the strict TRT guidelines revealed 4 studies. However after risk of bias appraisal was performed, one study remained for this review. Although the study was still considered to have a high risk of bias, the results suggested that TRT was a more effective treatment than tinnitus masking. The third systematic review from the Cochrane Database was not specific to tinnitus but looked at improvement in tinnitus for one of the outcome measures post surgery for Ménières disease(8). No significant improvement was noted.  
The last systematic review I will mention in this update is on cognitive behavioural therapy (CBT)(9). This study included 15 studies in its meta-analysis of randomly controlled trials and used tinnitus distress as the primary outcome and mood as a secondary outcome. The results of this meta-analysis indicated that CBT is effective in reducing annoyance and distress associated with tinnitus and that these improvements were maintained over time (median follow-up period: 6 months). The study also noted significant improvement in anxiety and depression, symptoms which frequently co-exist with or contribute to tinnitus distress. However as some of the trials included were of low quality, the authors do advise caution in interpreting the data but I would agree with them that a large well-controlled CBT trial on the diverse population of individuals with tinnitus is warranted.
Hopefully over the coming year we will see more robust randomised controlled trials on tinnitus to allow us to formulate an effective and evidence-based approach to the management of tinnitus.


1. Clinical Knowledge Summaries. Tinnitus clinical knowledge summary.  2010. [View]  

2. Kieran SM, Skinner LJ, Donnelly M, Smyth DA. A critical evaluation of Web sites offering patient information on tinnitus. Ear Nose Throat J 2010 Jan;89(1):E11-E14 [View critical summary

3. Swanepoel dW, Hall JW, III. A systematic review of telehealth applications in audiology. Telemed J E Health 2010 Mar;16(2):181-200. [View critical summary]

4. Hobson J,  in 6 E, El Refaie A. Sound therapy (masking) in the management of tinnitus in adults. Cochrane Database of Systematic Reviews 2010, Issue 12. Art. No.: CD006371. DOI: 10.1002/14651858.CD006371.pub2. [View]

5. Hoare DJ, Stacey PC, Hall DA. The Efficacy of Auditory Perceptual Training for Tinnitus: A Systematic Review. Ann Behav Med 2010 Jul 29. [Epub ahead of print] [View critical summary

6. Kamalski DM, Hoekstra CE, van Zanten BG, Grolman W, Rovers MM. Measuring disease-specific health-related quality of life to evaluate treatment outcomes in tinnitus patients: a systematic review. Otolaryngol Head Neck Surg 2010 Aug;143(2):181-5. [View critical summary

7. Phillips JS, McFerran D. Tinnitus Retraining Therapy (TRT) for tinnitus. Cochrane Database of Systematic Reviews 2010, Issue 3. Art. No.: CD007330. DOI: 10.1002/14651858.CD007330.pub2 [View]

8. Pullens B, Giard JL, Verschuur HP, van Benthem PP. Surgery for Ménière's disease. Cochrane Database of Systematic Reviews 2010, Issue 1. Art. No.: CD005395. DOI: 10.1002/14651858.CD005395.pub2 [View]

9. Hesser H, Weise C, Westin VZ, Andersson G. A systematic review and meta-analysis of randomized controlled trials of cognitive-behavioral therapy for tinnitus distress. Clinical Psychology Review 2010. Dec 23. [Epub ahead of print] [view critical summary]



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